# Class 10 Science Chapter 13 Magnetic Effects of Electric Current

Class 10 Science Chapter 13 Magnetic Effects of Electric Current The answer to each chapter is provided in the list so that you can easily browse throughout different chapters NCERT Class 10 Science Chapter 13 Magnetic Effects of Electric Current and select need one.

## Class 10 Science Chapter 13 Magnetic Effects of Electric Current

Also, you can read the SCERT book online in these sections Solutions by Expert Teachers as per SCERT (CBSE) Book guidelines. These solutions are part of SCERT All Subject Solutions. Here we have given Assam Board Class 10 Science Chapter 13 Magnetic Effects of Electric Current Solutions for All Subjects, You can practice these here…

### Magnetic Effects of Electric Current

Chapter – 13

GENERAL SCIENCE

Page – 224

Q.1. Why does a compass needle get deflected when brought near a bar magnet?

Ans :- A compass needle is a small bar magnet. When a magnet brought near the compass the north pole of the compass attracted by the south pole of the magnet and south pole of the compass attracted by the north pole of the magnet. so the compass needle deflected when brought near a bar magnet.

Page – 228

Q.1. Draw a magnetic field lines around a bar magnet.

Ans :-

Fig : Field lines around a bar magnet

Q.2. List the properties of magnetic lines of force.

Ans :- ( i ) They emerge from north pole of the magnet and enter the south pole.

( ii ) The two magnetic lines of force never intersect each other.

( iii ) Inside the magnet, they are from south to north pole.

Q.3. Why don’t two magnetic lines of force intersect each other?

Ans :- If two magnetic lines of force intersect each other it would mean that at the point of intersection, the compass needle would point towards two directions which is not possible.

Page – 229

Q.1. Consider a circular loop of wire lying in the plane of the table. Let the current pass through the loop clockwise. Apply the right-hand rule to find out the direction of the magnetic field inside and out side the loop.

Ans :-

As shown if fig. each section of wire produces its concentric set of lines of force. By applying right hand thumb rule, we find that all the section produce magnetic field directed downward at all points inside the loop while at the outside points, the field is directed upwards. Hence the magnetic field acts normally into the place of paper at the points inside the loop and normally out of the plane of paper at points outside the loop.

Q.2. The magnetic field in a given region is uniform. Draw a diagram to represent it.

Ans :-

Uniform magnetic field is represented by equidistant and parallel lines as shown. The parallel lines are close to each other, if the field is strong. Stronger the field, closer are the lines.

Page – 230

Choose the correct option.

Q.1. The magnetic field inside a long straight solenoid carrying current.

( a ) Is zero.

( b ) Decreases as we move to wards end.

( c ) Increases as we move towards end.

( d ) Is same at all the points.

Ans :- ( d ) Is same at all the points.

Page – 231

Q.1. Which of the following property of porton can change which it moves freely in a magnetic field? (There may be more than one correct answer)

( a ) Mass.

( b ) Speed.

( c ) Velocity.

( d ) Momentum.

Ans :- ( c ) and (d)

Page – 232

Q.1. In activity 13.7, how do we think the displacement of rod AB will be affected if

( i ) Current in rod AB is increased.

( ii ) A stronger horse-shoe magnet is used and

( iii ) Lengths of the rod AB is increased?

Ans :- ( i ) When the current in the rod AB is increased, force exerted on the conductor increases, so the displacement of the rod increases.

( ii ) When a stronger horse shoe magnet is used, the magnitude of the magnetic field increases. This increases the force exerted on the rod and the displacement of the rod.s

( iii ) Force is also directly proportional to the length of the ord. Hence rod will be displaced more if the length is increased.

Q.2. A positively charged particle (a particle) emitted from a nucleus and projected towards west is deflected towards north by a magnetic field. The direction of the magnetic field is

( a ) Towards south.

( b ) Towards east.

( c ) Down ward.

( d ) Upward.

Ans :- ( d ) Upward.

Page – 233

Q.1. State Fleming’s left hand rule.

Ans :- According to this rule, stretch the thumb, forefinger and middle finger of our left hand such that they are mutually perpendicular. If the first finger points in the direction of magnetic field and the second finger in the direction of current, then the thumb will point in the direction of motion or the force acting on the conductor.

Q.2. What is the principle of an electric motor?

Ans :- Electric motor is based upon Fleming’s left hand rule.

Q.3. What is the role of the split ring in an electric motor?

Ans :- In electric motors, the split ring acts as a commutator. i.e. it is a device that reverses the direction of flow of current through a circuit.

Page – 236

Q.1. Explain different ways to induce current in a coil.

Ans :- A current can be induced in a coil by

( i ) moving a magnet towards or away from the coil or vice versa.

( ii ) Changing current in the neighbouring coil.

Page – 237

Q.1. State the principle of an electric generator.

Ans :- An electric generator works on the principle of electromagnetic induction. When a closed coil is rotated in a uniform magnetic field with its axis perpendicular to the direction of the field, the magnetic field lines passing through the coil change and an induced potential difference and hence a current is set up in it.

Q.2. Name some source of direct current.

Ans :- Dry cell, button cell etc.

Q.3. Which sources produce Alternating current?

Ans :- Alternating current is produce by A.C generator. There are hydro-generator and thermal generators. Hydro generators convert P.E. of water to electricity whereas thermal generators convert heat energy of steam to electric energy.

Choose the correct option

Q.1. A rectangular coil of copper wires is rotated in magnetic field. The direction of induced current changes once in each :

( a ) Two revolutions.

( b ) One revolutions.

( c ) Half revolution.

( d ) One forth revolution.

Ans :- ( c ) Half revolution.

Page – 238

Q.1. Name two safety measures commonly used in electric circuits and appliances.

Ans :- ( i ) Electric fuse.

( ii ) Earthing.

Q.2. An electric oven of 2kw power rating is operated in a domestic electric circuit (220v) that has a current ratting of 5A. What result do you except? Explain.

Ans :- Here,       P   =   2kw

=   2000w

v    =   220 volt

I     =   ?

P    =   VI

Or   I  =  P / V

= 2000 / 220

=  9.09 A

A current of 9.09A will flow in the circuit. Since the current rating of circuit is 5A, the fuse rating if inserted in circuit will burn up. If no fuse has been put in the circuit, there may be a fire.

Q.3. What precaution should be taken to avoid the nozoverloading of domestic electric circuits?

Ans :- ( i ) The wires used in the circuit must be coated with good insulating materials like pvc etc.

( ii ) Separate circuit should be there for heating appliance.

( ii ) High power appliances like air-conditioner, refrigerator, water heater etc, should not be used simultaneously.

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